In the latter half of the twentieth century, there began a phenomenon known as the information revolution. While the information revolution is a historical development broader in scope than any one event or machine, no single device has come to represent the information revolution more than the digital electronic computer. The development of computer systems has surely been a revolution. Each year, computer systems grow faster, store more data, and provide more applications to their users.
The reduced cost of computing and the general availability of digital computing devices has brought an explosion in the volume of information available on such devices, and in the variety of applications to which such devices are put. For some years now, inexpensive “personal computers” have been available for personal use at home or for the use of a single individual at a place of business. Increased miniaturization has made it possible to design portable “laptop” computers and personal digital assistants (PDAs). These devices, together with the prevalence of the Internet, have brought digital information and computing capabilities to the public on a mass scale.
One consequence of these developments is that individuals who, for whatever reason, lack access to computer technology, are at a disadvantage, and this disadvantage grows in significance with each passing year. For example, it is now common for colleges and universities to communicate with students concerning schedules, assignments, grades and so forth, over the Internet. In some institutions, this reliance on the Internet has reached an extent that it is difficult or impossible to complete required courses without use of the Internet, a trend which is likely to continue. Such a use of digital technology and the Internet shows signs of further expansion into high school and lower level curricula.
Despite these developments, many individuals remain either unable to perform basic tasks involving the use of a computer, or less than proficient in the performance of such tasks. There are many and various reasons for these deficiencies, not all of which are addressed herein. For some individuals, lack of computer capability is due primarily or partially to physical handicaps, which make it difficult or impossible for the individual to use conventional digital input and output devices.
One particular group of individuals who find it difficult to use many common digital devices is the visually impaired. Most digital devices present output in the form of a visual display, which a visually impaired person may find difficult or impossible to read. Furthermore, digital input devices, although not strictly speaking visual, often rely on an interaction of visual output with a selection mechanism, such as a mouse.
Various mechanisms exist in the art to compensate for visual impairments to provide at least some degree of function to at least some visually impaired individuals. For example, for certain individuals with mild visual impairments, an output display of a digital device can be programmed to display information in a magnified form, or using special fonts, colors, or other characteristics, to make it easier for the visually impaired user to see. For individuals with more profound visual impairments, text-to-speech synthesizers are sometimes used to render textual information in audible form. These are various other techniques provide some degree of access to visually impaired users.
As useful as these conventional mechanisms are, in general visually impaired individuals remain at a disadvantage vis-a-vis people of normal vision when it comes to using digital device technology. Some forms of information, particularly graphical information, is difficult or impossible to render in audible form. Still other information could be rendered audibly or in some other suitable form, but there are other problems with doing so, such as privacy, security, interference, or similar concerns. In some cases, modification of an interface may be so radical that it just hasn't been done. Finally, even though visual information can be rendered in audible form, it may simply be a much slower and less efficient means of conveying information to the user, so that the visually impaired user still suffers a considerable disadvantage.
A need therefore exists for continued improvements to the way in which visually impaired persons interface with digital devices, and in particular to the way in which information from a digital device is conveyed to a visually impaired user.